I finally got my Kadee couplers in and after struggling a bit, managed to get them installed, but what I find is that they don't seem to allow me to tighten the screw as much. This isn't a problem for two of the cars, but one of them I can't tighten the screw at all. Anything short of falling off results in the coupler not centering itself. It stays to one side or the other - it's stiff. Is there a solution for this other then replacing the coupler box, something I'm not sure I'm prepared to do. Does the coupler box just need some sort of lubricant to get it to work well?

I ordered the Kadee #148. That's the right ones, right. "HO Whisker Coupler, 9/32" Center (2pr)". Correct?

I'm probably not going to buy a 25 pair pack, as we only have one engine and 3 cars. If these Kaydee couplers are pretty much break-proof, then it's cheaper to just buy two 2-pair packs. A lot cheaper. If I knew we'd be expanding I'd buy a 25 pack, but my kids are 8 and 9 and who knows if they are going to stick with it.

I take it if I were to buy the height gauge, there's no point in doing that if I don't also buy those fiber washers to adjust the height? Or is there some other way to adjust the height? It didn't look like it, but I want to be sure. Do those fiber washers have a part number?

EDIT: for now I decided just to order the couplers. Two 2-pair packs for $8.60 shipped from amazon.

Ok, thanks. I'll give them a shot. Do I need to change all the couplers at once, or can they work with the (non-broken) stock couplers? Also, does anyone have a good source for buying small quantities of couplers (or other parts) at a low cost?

I think I'd like to stick to the Bachmann parts or equivalent. I want an easy replacement, at least for now. What version of the coupler do I need or how can I figure that out by looking at the couplers on there?

Also, how do you adjust the height of the couplers on there? Some are higher/lower then others. Do you just try to bend them?

My son bought a Bachmann Thoroughbred train set and he loves it, but two of the couplers have broken already. I want to buy replacements, but there are so many different versions it seems. What type does his train need? "E-Z Mate® Center Shank - Medium" or something else? Also, what is the difference between the those and the "E-Z Mate® Mark II" couplers? Do I want short, medium or long? Also, are any of these stronger then the ones that came with the train/less likely to break?